Abattoirs butcher carcasses into cuts of meat for retailing such as chicken thighs, lambs fry, sheep kidneys and the like. These are placed in cardboard cartons which take about 25 kg. The cartons are about 500×500×200 mm. These are covered with lids of larger size and closed by three loops of polyester tape. The cartons are stacked on pallets in the coolroom before being freighted in refrigerated trucks to customers. Ocean fish and shellfish are similarly packed. Sometimes crushed ice is added.
Delays and accidents inevitably result in leakage and consequent deterioration of the cardboard. This may lead to wasteage of the food and loss to the shippers. The cartons may be recycled but they constitute a cost to the packing industry and the consumer.
PCT/US01/49291 describes a stackable carton with liquid tight corners created by diagonal fold flaps. The general cruciform shape of the blank in plan is evident. Such cartons are for light use only.
EP19840302640 shows a paperboard carton made waterproof by coating. The carton is for a small quantity of milk and has diagonal fold flaps.
U.S. Pat. No. 2,495,807 presents a double walled meat carton which is built up from a flat blank with corners reinforced by diagonal folding flaps. These pass through a glue applicator and the flaps are folded by hand. These rely on paraffin wax coating to render them suitable for containing meat but the cartons need only be strong enough to resist distortion when picked up by one hand.